Yielding bit and tap chuck.



W. L. PROGUNIER. YIELDING BIT AND TAP UHUUK. 'APPLIOATION FILED JUNE 10, 1907.

900,122, Patented Oct. 6, 1908.

' To all whom e t mmforming a part thereo topermit the tool to WILLIAM PROOUNIER or cHIoAeo, ILLINOIS.

Ymmme m AND TA? annex.

No. 900,122. Specification of Application filed June 10, 1907. Serial no. 818,087.

Be it known that I, WILLIAM L, PR0- opnmn, -a citizen "of the'llnited States, resldin at Chicago, in' the county of Cookand tate of Illinois, have invented newand useful Improvements in Yielding Bits and Tap Chucks, of which the following is a specification, reference being to the drawings This invention is designed 'to lprovide means for holding a bit or tap re easab'ly. and securely against disengagement, but yieldingly as to the gripfor rotation so as slip when otherwise itwould be broken. a I

It-consists in the features of construction which are shown and described, as indicated by the claims.

In the drawings :.-Figure '1 is an axial section of a chuck embodying the invention, showing it without a tool, and at most relaxed position of the spring which eflects frictional driving engagement. i Fig. 2 is a similar view showing the tool. in place. Fig. 3 is a section at-the line 3 -3 on Fig. 2. Fig. 4; is a section .-at the line 4= 4 on Fi 1. Fig. 5 is a section at the line 5-5 on Flg. 2.

I Fig. 6 is a detail elevation of the end portion of the jaw-closin plunger and a spiral spring. thereon in axiagsection. Fi 7 is a side elevation of the shank jpor tlon of a tool ada ted to be used with the device.

hestemor shank, 1, of thetool to be held extends axially through a conical holder, 2, and between the two -Jaw pieces, 3, 3, which are lodged in the up er part of said conical holder, 2., which is edged in'an interiorly conical sleeve, 10, which is in turn telescoped inthe cylindrical cavity of the outer shell, 7 of the chuck, being free tomove longitudinally therein to a limited extent, but prevented from rotation relative .thereto by the projections or lugs, 10, of the sleeve which engage in the slots or end notches,:7,-of the shell. The cap, 12, is screwed on to the shell, 7, housing a spring, 11, lodgedin' the cap and stopped between the lower end of the sleeve, 10, and the end of the cavity. of the cap, the latter havinga central opening throu h which the tool protrudes- The cap, it wi be understood, is to be screwed up "onto the shell for tensioningthe spring, 11,.

' to cause it to press the sleeve, '10, on to the .conical holder, 2, to cause sufficient frictional en ement between the two elements for l The holder, 2, has a cavity oblong in cross section at the upper end tapering substantially to correspond with the taper of the conical holder, 2, from the upper to the lower end just back of which the said ta ering oblong cavity becomes, reduced in wldth by its taper to substantially the diameter of the aperture in the lower end of the taperin holder through which the tool is inserte The two jaw pieces are themselves tapered, their outer sides or edges being fittedto the opposite surfaces'of the oblong tapering cavity, 2 and having their facing surfaces each provided with a longitudinal V shaped groove, 3, for receivin the upper squared end, 1, of the tool to grip the latter for rotation.

a pin, 3" projecting fromone of them and taking loosely into the other for the purpose of retaining .them in directly opposed rela-. tion so that. they will keep together in sliding. up and'down in the tapering oblong cavity, 2, of the holder, 2. A spring, 4, coiled about t the pin, 3", reacts between the two jaw pieces edges seated against the opposite converging sides of the cavity, 2*. The angular convergence of these opposite sides of the cavity is such that the operation of the spring, 4, tending to force apart. the two jaw pieces causes them to normally assume a position will be accommodated at the full spread which the spring, 4, tends to cause, and, if depressed in the cav1ty,-to recover that positionby the action of the spring when released-from the depressing force. Atthe position which the jaw pieces thus norturn when forced away therefrom they are 8 read apart so widely as to readily admlt t e squared upper end or head, 1, of the tool, and when forced downward'in said oblong cavity they are v closed together by the convergence of theopposite walls gri pin'g said gs uared head. Each'of the an u ar corners theend, forming a notch or recess, 1; Each ofthe'jaw pieces, 3, 3,:1is provided with a slight rejection, 3, which protrudes. into the V-.* aped recess of the inner face of the jawgiiece' for engaging a notch, 1, of the tool ea when'the atter is passed u between the jaw pieces .to be rip ed thereliy. When the jaw pieces-are c ose together by being.

the head, 1, is undercut a' little back of g The two jaw-pieces 3,3, are connected by tending to hold them apart with their outer in the height of" the cavity at which they mally assume and to which they tend to re-] forced downward in the oblong cavity of the holder the tool being gripped between them is also retained by the en agement of said projections, 3, in the note es, 1, so that if the grip should be relaxed slightly the tool will not fall out. Moreover the tool would be liable,'i n the absence of such retaining devices, to be pulled out of the jaws by any force tending to give it a stron longitudinal pull, as when the chuck is .su denly backed up from. the work while the tool is engaged therewith. Such undesirable disengagement of the tool from the jaws by longitudinal pull is prevented by the presence of the notches in the tool headand the projections for engaging therewith in the jaws,

' because that engagement transmits such ull directly to the jaw pieces crowdin t em down 1nto the sleeve even more tight y than they are held by the pressure of the sprin 15. For holding the aw pieces pressed own I in the tapering cavity, 2, of the holder, 2, "soas to enga e and grasp for driving the square end 0 the tool andto permit the jaws to yield back to admit tools of differ ent sizes up to the limit of spread of the jaws which the size of the cavity, 2, will permit, there is provided a plunger, 5, ex-

osed to the action of a spring, 6, which is odged in the bore, 7*, made in the stem of the shell to accommodate the plunger on whose upper end the sprin reacts, the lower end or head of the plunger ein arranged to rest upon the bridge piece, 8, w ich extends ;across the upper ends of the jaw pieces for bearing upon them both to transmit to them both alike the thrust movement of the plunger.

As thus far described the chuck will operate for receiving tools of different .sizes and-holding the tool thus received positively between the jaw pieces and for rotating it without yielding until the limit of frictional driving enga ement between the conical holder, 2, an the conical sleeve, 10, held pressed in frictional engagement by the s ring, 11, is exceeded by t e resistance of t ework. As soon as the resistance of the vtheir norm action of their spreadin 1 slot, 2" of the te ar enough to disengage the t1on s,'3,"from the notches, 1, of t the of the- V-shapedhotches of the -headfso that the tool is not only free from the stem for securing it at any -slightly greater in rectly against the 'pl jaws, but also from the retaining engagement of the projections, 3, and 1s entirely free, therefore, for removal. Without some further revision, which will be hereinafter described, the u ward or inward pressure against the tool or performing its work before reachin the limit of its strength for which the rictional grasp of the conical driving surfaces under the tension of thespring, 11, is adapted, would tend to force upward the jaw ieces, 3, 3, com ressing the sprin 6. In t is action the aws would loset eir grasp u n, and driving enga ment with, the too To prevent this e ect there is provided a set screw, 16, set in through the side of the shell or shank thereof in position to impinge against the stem of the plunger entered in the bore, 7", to clamp sition to which it may be forced upward in entering a tool of such size as to require the jaws to be forced upward in the oblong cavity of the shell in order to admit them. When the plunger is thus provided against yielding upward'in a manner which would loosen the rip of the jaws, the wear which will occur tween the upper end of the jaws and whatever is provide for takin the wear,-in the construction shown, the ridge-piece, 8,-

and the lower end of the plunger, 5, when sli ping occurs from overwork on the tool, wil soon cause a little play between the wearing parts, and the jaws yielding in this play Wlll relax their grasp on the tool. To prevent this result the lunger, 5, has a head, 5, which rests upon the bridge, 8, movable longitudinally with respect to the plun er for a' short distance. In order to have t is action, the head has a spindle or stem,'5",

for which an axial bore, 5, is'provided in the endof the plun er, and the head being iameter than the plunger so. as to constitute a flange thereof rea ceives the pressure of the spring, 15, about the plungpr and is sto ped at its upper end a ainst t e upper en of the cavity of the sell, 7. A cross pin, 5 in the spindle, 5", of the head being engaged in lateral slots, 5', in the plunger to retain the headland check and limit its movement outward with respect to the 'lunger under the stress of the sprin 15. he re uirement for the purpose or which the p un r is provided with a yielding head as'descri d is obviously that the head shall yield relativel to the plun-' ger, but itis also necessary it at the spring,

15, shall be compressedso as to be under tension when the plunger is secured bythe set screw; and if'said spring, 15, reacted div er it would have to be weaker than the spring, 6, in orderto be thus .comprewed inthe process by whichothe plunger is forced up "against"the latter vspring. The smallhgmce. available for the spring, 6, makesit cult to provide at that 6 a inst the top of the cavity of the shell as own, and make the two springs, 15 and 6, of such length that they shall both be compressed during all the upward movement of the plungerininserting the tool and tensioin mg the spring, 11, to the proper degree for frictional drive." By this means the spring, 15, is compressed during the setting ofthe tool to asuflicient tension to hold the jaws almost with the same effect as if they were positively stopped, and at the same time with capacity for reaction to compensate for wear which would .not be afforded by the positive stop.

'With this construction the set screw, 16, being relaxed so as not to engage the plunger stem, the spring, 6, holds the plun or down- .ward relatively to the shell, 7, and t e s ring, 15, holds the flange of the plunger ownward thereon to the limit, so that the plunger device operates with yielding pressure upon described, and with the effect of holding the Jaws down m-the oblong cavityof the holder,

3, ready for receiving. and engaging the 30 s uared headof the tool when it is inserted. pon pushing the tool up into place, entermg its head between the jaw pieces with whose projections, 3, the notches, 1, of the head-become engaged, the cap, 12, will be screwed up for forcin the sleeve, 10', up onto the holder, 2, until therequisite pressure for frictional engagement for driving the tool, according to its strength, is obtained. The'larger the tool and its squared head, the farther u in thetapering cavity of the holder, 2, will the jaws, 3, be pushed in order to admit'the head into their, V- sha. ed notches; and the ezgtra length of the hol er, 2, above the top of the jaws at the lowest position which" the-latter can 'descend in the tapering cavityof the holder is designed for accommodating tools vwithin certain range as to size. Such u ward and resultant spreading movement 0 the jaws carries upward the entire plunger, 5,-against the resistance of the spring, 6,- the springs,

' 15and 6, being both com ressed at the same.

time, as above explaine so that both are under proper tension bythe time'the'tool is tlon and preventing any com ression ofor reaction by the spring, 6, in t e further use -*-1 st motionnas describ In order to prevent heating and excessive Wear ofthe parts when thetool is'stoppegi the top of the holder, 4, and the .upper end gageinent with a tool head to iii-place and engaged by the jaws. The set screw, 16, will now be tightened on to .the spindle, 5", holding the latter in definite posiby resistance of the work beyond the limit to which it is adjusted, it is preferred to interpose a fiber wearing washer, 20, between of the cavity in the shell.

1. A to0l-holding chuck comprising, in combination with a driven holder, a pair of jaw pieces lodged inthe holder and engaged therewith for rotation, having V-shaped recesses for engaging a tool-head to rotate it positively, and having projections extending into the recesses. transversely thereof for enprevent its longitudinal withdrawal. 2. A tool holding chuck comprising a holder for the tool provided with a longitudinally tapering cavity; tool gripping jaws lodged in sai avity, said jaws having coiiperating features for engaging a tool against relative longitudinal movement when the jaws are closed upon the tool head, and

spring for pressing the jaws into the tapering cavity to close tht nn together onto the tool. the upper ends of the aw pieces, as already a 3. A tool-holding chuck coinprising a tool I holder and a cooperating element for rotating the same by frictional engagement-therewith, said holder and cooperating element being correspondingly tapered for seating one upon the other for said frictional engagement; a spring for yieldingly pressingthem into engagement, the holder having a longitudinally tapering cavity; a pair of tool-gripping jaws lodged in said cavity and adapted to be closed together for gripping the jaws by movement in'the cavity toward the smaller end; a stop which resists the movement of the jaws in the opposite direction, the reaction of said spring being opposed to the resistance of such sto'p.'

4. A tool holding chuck comprising a holder having a longitudinally tapering cavity; a pair of tool-gripping jaws lodged in the cavity and adapted to be closed together by movement therein toward the smaller end thereof, said "jaws having features for en-. gaging a tool toresist longitudinal withdrawing movement of the tool from the jaws; a spring reacting-between the. aws to spread them for releasing the tool; a stop which opposes, the movement of the aws withdrawing from the holder, and means such stop. t

v 5. A tool -h0lding chuck comprisi-n'gf an outer shell; a holder for the tool withi'n'the shell,"and a driving element for the holder having positive engagement with the shell and frictional engagement with .theholder;

a. spring-for pressing the two parts into engagement, and means .for ad ustmg the tension of the spring; jaws forgrippmg the for yieldingly pressing the holder toward tool lodgedxin the holder, said jaws and for rotation and ada ted to be closed. to-

jaws to be closed together by a longitudinal movement relative to the holder in one direction; means carried by the shell for stopping the jaws a inst movement for wit drawing from t e holder, the reaction of said spring being in the direction opposed tosai sto s 6. A tool-holding chuck comprising a shell; a holder within the shell; coo ratin jaws, within the holder engaged t erewit gether by longitudina movement in one direction'in the holder; a ring which tends to spread them; a stop w ich resists longitudinal movement in the direction required for such spreading; an element engaged I positively with the shell and frictionally with the holder for rotation of the latter,

and means for yieldingly pressing said element toward said stop for such frictional engagement.

7; A tool-holding chuck comprising a holder having a longitudinal tapering cavcombination with a ity tool-gri ping jaws lod d in said cavity adapted to he closed togeti er for gripping the tool by -movement toward the smaller I end of the cavity; said jaws having features for en agement with a tool to prevent longitudinai withdrawal of the tool while the jaws are closed upon it a spring tending-to spread the 'aws for 'disen gin said features; a yie ding sto whic yie dingly opposes the longitudina movement of sald 'aws 1n the holder necessary for such sprea ing. 8. A tool-holding chuck. comprising a holder for the tool provided with a longi- -tool-gri ping jaws lodged in said cavity and adapt to be-closed together by movement toward the narrower end thereof; an adustable stop which resists the movement 0i 7 the jaws outward from said cavity for rehead which movement of the jaws, and a spri leasingthe tool; means for positively securing said stop 'the stop having a yielding directly opposes the outward operates on said head to hold it toward the 10, Atool-holding 'chuckwompri in combination with' a holder, a"pair b i -jaw pieces lodged in the holder, engagedtherewith I for rotation,- and adapted or receiving and' e g-a'tool head for positive rota tion 0 1e -i-latter, said jaw pieces having cavity for closing tool also devices for en aging a tool head against longitudinal with rawa 11. A tool-holding chuck com rising a driven holder having a longitudina y tapering cavity; jaw pieces lod ed in the cavity and thereby engaged wit the holder for rotation; means for-yieldingly pressing the jaw pieces toward the narrower end of the them together, said jaw pieces, having devices for transverse engagement with the tool-head lodged between thercrli to prevent withdrawal of said tool hea 12. A tool-holding chuck comprising a holder for a tool provided with a longitudinally tapering cavity; tool-gripping jaws lodged in such cavity having means for engaging a tool against longitudinal withdrawal, and a spring for pressing the jaws into the'tapering cavity to close them together for such engagement.

13. A tool-holding chuck comprising a holder having a longitudinally tapering cav-' ity; a pair of tool-gri ping aws lodged in the cavity and adapte to be closed together by movement therein toward the smaller end thereof, said jaws having means for engaging a tool against longitudinal withdrawal thereof; a spring reacting against the jaws to spread them for releasing the tool; a stop which opposes the jaws withdrawal from the holder, and means for yieldingly pressing the holder towards such stop. 14. A tool-holdin chuck comprising a frictionally driven holder; an element cooperating with such holder for frictionally communicating the driving movement, the holder havin a tapering cavity" tool-griping jaws lod ged in such cavity tor rotation by theholder and adapted to be closed together for. grip ing the toolbetween them by movement of the ews in the cavity toward thesmallerend; a spring tending to s read the jaws to release the tool; a sto evice which opposes the movement of t e jaws withdrawing from the holder, and means operatin u on the holder-driving element for yiel ing y pressin it into frictional enagement with the older, such pressure ing in the direction opposed to the resistance of the stop.

15. A tool-holding chuck in combination with a holder having a tapering cavity; toolgripping jaws lodged in the cavit ada ted to be closed together for griplping t e too by movement toward the sina or end of the cavity, said 'aws having features for.engaging a tool w "ch ma be between the jaws to prevent the longitu inal withdrawal of the a spring w 'ch tends to spread the jaws to release the tool; a stop for resisting the lon 'tudinal-movement of the-jaws in the hol er n jaws-; means Y or positively" securing the stop for such 3 reading; a spring 1 winch yleldm y=presses t v estop toward the ing, one upon the other,

against yielding movement, said stop having a head by-which it opposes said longitudinal movement of the aws, said head being lodged on the stop for movement longitudinally thereof,iaml a spring which yieldingly protrudes the head toward'the 16. A tool-holding chuck comprising a tool-holder and a cooperating element for rotating the same by frictional engagement therewith, said holder and cooperating element being corresponding tapered for se'at-' for such frictional engagement; at s )ring for yieldingly pressing them into rictional engagement, the holder having a longitudinally tapered cavity; a pair of tool-gripping jaws lodged in said cavity and adapted to be closed to ether for gripping the tool by movement n the cavity .toward the smaller end; a springpressed stop device which yieldingly resists the movement of the jaws in the opposite direction, and means for positively securing said yielding sto i 17. A tool-holding chuck comprising a tool-holder and a 006 erating element for rotating the same by rictional engagement therewith, said holder and cooperating element being correspondingly tapered for seating one upon the other for such frictional engagement; a spring for yieldingly pressing them. into engagement and means for varying the tension of the spring, the holder having a longitudinally tapering cavit a pair of-tool-gripping jaws lodged in said cavity and adapted to be closed together for gripping atool between them by movement in the cavity toward the smaller end; a stop which resists the movement of ,the jaws in the opposite direction; a spring which yieldingly presses the stop to afford such resistance, and means, for positively securing the stop against yielding, the last-mentioned spring. being lighter than the spring which affords the pressure for frictional driving engagement.

In testimony whereof, I have hereunto set my hand at Chicago, Illinois, this 7th day of June, 1907.

. WILLIAMTJ. PROCUNIER.

Witnesses:

J S. ABBOTT, 'M. GERTRUDE Am. 

